The present invention is related to plasma processing systems. In particular, the present invention is related to plasma processing systems including coils for tuning plasma distribution.
Plasma processing systems, such as capacitively coupled plasma (CCP) systems and inductively coupled plasma (ICP) systems, are employed in various industries for fabricating devices on wafers. For example, the industries may include semiconductor, magnetic read/write and storage, optical system, and micro-electromechanical system (MEMS) industries.
A plasma processing system may generate and sustain plasma in a plasma processing chamber to perform etching and/or deposition on a wafer such that device features may be formed on the wafer. When a wafer is processed in an existing plasma processing system, the plasma density at the center portion of the wafer or near the center portion of the wafer may be substantially higher than the plasma density at the edge portion of the wafer or near the edge portion of the wafer. As a result, plasma processing rates (e.g., etch rates) may be substantially non-uniform or substantially inconsistent across the surface of the wafer, and the manufacturing yield may be undesirable.